how to fix P0420 code in my Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a level surface and securely lifted using jack stands.
• Disconnect the negative battery terminal.

2. Inspect and Replace Oxygen Sensors

• Tools Required: Oxygen sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the oxygen sensor socket to remove the sensors.
  4. Install the new oxygen sensors by threading them into place, then tighten to the manufacturer's torque specification (usually around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Examine and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, penetrating oil
• Sub-steps:
  1. Inspect the catalytic converter for cracks or other damage.
  2. If replacement is needed, unbolt the catalytic converter from the exhaust manifold and exhaust pipe.
  3. Apply penetrating oil to bolts to ease removal if rusted.
  4. Install the new catalytic converter, ensuring proper alignment and secure it with bolts tightened to the specified torque (typically around 30-50 lb-ft).
  5. Reconnect any hangers or brackets.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Start the vehicle and perform a test drive to ensure the issue is resolved and monitor for any new codes.